Extension light



R. H. CARTER Oct. 19, 1954 EXTENSION LIGHT Filed March 20, 1951 I. n w wm n I n v FIG. 2

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5 INVENTOR.

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lITTOk/VE x5 Patented Oct. 19, 1954 UNITED STATES PATENT OFFICE 2Claims.

(Granted under Title 35, U. S. Code (1952'),

sec. 266) The invention described herein may be manufactured and used byor for the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in portable lighting devices andmore particularly pertains to improvements in extension lamps adaptedfor use in aircraft eockpits, gun turrets, and for like uses.

Extensions lamps theretofore employed have been bulky, heavy, cumbersomein use and subject to frequent breakdown in service. The provision offocusing means and the external switching means employed have increasedsuch disadvantages, particularly in uses where the operator must weargloves or mittens.

The principal object of this invention is to provide an extension lampthat is simple in construction, of convenient size, light in weight, andsturdy and facile in use.

Another object is to provide an extension lamp that can be manipulatedfacilely for focusing and for switching on or off, and can provide suchop erations readily under extreme service conditions.

A further object is to provide an extension lamp that can emit a redlight and a white light succesively and wherein the size of the whitelight emitted can be varied facilely.

Still another object is to provide an extension lamp having acam-actuated on-off switch that is protected adequately against entrythereon of foreign substances that can be encountered during extremeservice conditions.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing wherein Fig. 1 is a plan viewof an extension lamp, partly broken away to show certain features ofconstruction, showing a preferred embodiment of the invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a plan view of the extension lamp shown in Fig. 1, partlybroken away, showing the device in fully retracted position;

Fig. 4 is a section taken on the line 4-4 of Fig. 1; and

Fig. 5 is a section taken on the line 5-5 of Fig. 1.

Similar numerals refer to throughout the several views.

similar parts The lamp socket and switch mount of the device comprises agenerally cylindrical member I I made .of a dielectric such as hardrubber or Bake lite. Said member I I comprises a cylindrical buttportion i3, an integral medial semi-cylindrical portion l5, adapted tocarry the cam and switch "iembers hereinafter described, and an integralt lindrical head portion I! adapted to carry the lam socket hereinafterdescribed, so that the end walls l9 and2l of the butt portion l3 and thehead portion ll respectively, with the flat 23 of the medial portion l5,define a transverse central slot. The medial portion l5 and the headportion I! define a cylinder of smaller diameter than that defined bythe butt portion I3 so that the peripheral portion of the wall 19provides an abutting shoulder for the sliding tube assembly hereinafter.described.

Lamp socket 25, which carries lam 21, is seated in a bore 29 extendingaxially through the head portion I! and extending partly into medialportion 15. The terminals of said socket 25 are a stepped lug 29 securedto the axial pin 3! of said socket and extending over .a portion of theflat 2.3 and a washer 33 having an integral lug 35 secured to saidsocket in contact with the shell 31 thereof and insulated from the pin3|.

Strap 39 extends over stepped lug 29 and is fastened upon flat 23 byscrews 4| and 4.3, thereby retaining said lug and the socket25 inposition. Moving contact .45 is .soldered upon said strap 3.9, theresilient arm of said contact extending rearwardly towards the buttportion 13. Stationary contact 41 is fastened upon flat 23 by screw 49,the contacts 45 and 4'! being so disposed as to be closed normally.

Cam ill is made of a dielectric material and is carried rotatably onscrew 43. Said cam 5 l is so dimensioned and shaped that a portion ofsaid cam extends to the diametral limit of butt portion f3 when contacts45 and ll are closed, and so that rotation of said cam to a positionwithin such diametral limit causes said cam to move contact 45 out ofengagement with contact 4].

Grommet or fitting 53 is threaded in a bore 55 tapped axially in the endof butt portion IS. A bore 57 communicates between bore 55 and wall l9so that a first conductor 59 can be led from the screw 49 of contact 4'1through said bore 5'! and fitting 53, and a second conductor fill can beled from lug 35 through said bore 5'! and fitting 53, said conductors 59and BI being connected to a suitable source of current.

The sliding tube assembly of the device comprises a tube 63 adapted tofit slidably over head portion l1 and medial portion l and to abut theperipheral portion of the wall I9, so that said tube 63 can rotate saidcam 51 and thereby move contact 45 out of engagement with contact 41.The head portion 65 of said tube 63 is of enlarged diameter to provide ashoulder 61 for abutment of the outer shell or sleeve hereinafterdescribed. A triangular window 69 is cut in the mid portion of said tube53, the base of such triangle lying normal to the longitudinal axis ofsaid tube and the apex of such triangle extending towards the headportion 55. Red glass lens H is secured in the end of head portion 65 byretainer ring l3.

To secure the sliding tube assembly on the cylindrical member I! andpermit relative sliding of said assembly and said member, a slot 15extends along substantially the length of the head portion l1 and medialportion l5 of said member II, and carries a slug I1 slidably therein.Countersunk screw 19 passes through the wall of said tube 63, proximatethe end of said tube distal head portion 65, and is threaded into saidslug ll. Thus member 63 can be retracted to the position shown in Fig. 3to press the cam 5| against contact 45 and break the circuit, or can beextended to the position shown in Figs. 1 and 2 to be disengaged fromthe cam 5!, to permit contacts 45 and 4.1 to engage, and to present thelamp 2! at the window 59.

The outer shell of the device comprises a tube 8| fitted slidably overtube 63 and butt portion I3, said tube 8| being secured to said buttportion l3 by setscrews 83 and abutting shoulder 61 when said tube 63 isretracted fully, as shown in Fig. 3.

In order to restrain movement of the tube 63 relative to tube 6|, asuitable means to increase friction between tube 63 and member H isprovided. Such means can be a flat steel spring 65 that is held in amilled slot 87 in the head portion I! by a screw 89 and bears againstthe inside of tube 63.

In the operation of the device, alternating current from a suitablesource is fed to the lamp 2'! through conductor 59, contact 4?, contact45, strap 39, lug 29 and pin 3| successively, and is fed to the saidlamp 2? through conductor 6|, lug 35 and shell 31 successively.(Obviously, direct current could be employed through the same circuit.)It is apparent, then, that the making or breaking of contacts 45 and 4'!control illumination of the lamp. 7 7

Such contacts are broken when tube 63 is in fully retracted position,said tube 63 pushing cam 5| inward to move contact 45 away from contact41. When tube 63 is advanced a distance sufficient to clear cam 5|, saidcam 51 is pressed outwardly by contact 45 against tube BI, and in suchposition contact 45 engages contacts 41 to complete the circuit. In suchposition of the elements of the device, light is filtered through thered lens H and affords the conventional safety light.

When tube 63 is advanced somewhat further from its telescoping relationto tube 8!, suitable focusing of the light emitted is efiected. When.

tube 63 is advanced still further, a pin point of white light is emittedthrough the now exposed apex of the triangular window 69. With continuedadvance of the tube 63, the size of the triangle exposed beyond the endof tube 8| increases until a maximum is reached with exposure of theentire window.

It is thus apparent that the subject device provides an aircraft cockpitand gun turret extension lamp that is compact, light in weight, sturdyand facile in operation, and adapted to provide conveniently both afiltered and focused safety light and to pass white light that can bevaried from a pin point ofillumination to full opening. In the structuredisclosed, the safety light is illuminated first, a desirable and attimes essential feature, and the simple switch means provided is wellprotected mechanically.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:

1. An extension light comprising a cylindrical member carrying a lamp inone end thereof and a switch having a spring contact in a transversecentral slot thereof, means to supply current to said lamp through saidswitch, a cam mounted on said member in said slot, said cam being urgednormally partly beyond said slot by said contact and being adapted tomove said contact out of closed circuit position when depressed intosaid slot. A first tube mounted on and encasing said member, a secondtube carried slidably within said first tube and over said member, saidsecond tube having a lens in one end thereof and a triangular aperturein the wall thereof, said aperture being in a position to reveal an apexthereof initially upon outward movement of said second tube, said cambeing depressed into said slot during inward movement of said secondtube, and means to limit sliding of said second tube relative to saidmember.

2. An extension light comprising a cylindrical member carrying a lamp inone end thereof and a switch having a spring contact in a transversecentral slot thereof, means to supply current to said lamp through saidswitch, a cam mounted on said member in said slot, said cam being urgednormally partly beyond said slot by said contact and being adapted tomove said contact out of closed circuit position when depressed intosaid slot, a first tube mounted on and encasing said member, a secondtube carried slidably within said first tube and over said member, saidsecond tube having a filtering lens in one end thereof and a triangularaperture in the wall thereof, said aperture being in a position toreveal an apex thereof initially upon outward movement of said secondtube, said cam being depressed intosaid slot during inward movement ofsaid second tube, and means to limit sliding of said second tuberelative to said member.

References Cited in the file of this patent UNITED STATES PATENTSGermany Feb. 10, 1914

